What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

AV-500003

JDA_BTR

Well Known Member
I was able to find through Stein this component that is available to install on the lower panel for electrical distribution, the "AV-500003". I don't have a way to post the file here describing it.

Basically it has a terminal post for battery, terminal post for alternator on either side of a 60A CB. Battery post has a shunt resistor to a main bus, alternator post has a second shunt to the same main bus; main bus is on a PCB. There is an avionics relay with an avionics bus as part of the setup.

PCB feeds 27 ATC fused outputs, a few unfused outputs, all via a pair of D-Sub connectors. It also has shunt outputs for an alternator ammeter and a battery ammeter.

I like it, it is a neat solution, but it requires both the battery connection and the alternator connection wires to be brought into the cockpit. In my case there would be a third fat wire for the standby alternator. (Main alternator "outside" the CB, and backup "inside" the CB I think). The backup alternator would have a fuse link or inline fuse to permit that. It keeps from having to put shunts on the firewall. It explains why shunts aren't part of the per-plan firewall layout because Vans figured we would put it all inside.

Downside is that the alternator to battery charging path is all the way into the cockpit and back out to the battery. Not sure if that matters.

Thoughts?
 
Last edited:
Thinking about it some more. If I tie the standby alternator after the primary alternator CB on this panel, I am subject with both to a possible single shunt failure. If I tie the standby alternator into the starter post outside the firewall then it feeds into the panel via the battery side of the fuse panel and then a shunt failure could take battery/standby or primary alternator but not both. Dual failure required not single?

How likely is a shunt failure? This shunt is a surface mount resistor.... Failure seems very unlikely to me. Best data I can find in assembly shows 0.01% in 1000 hours, but some are better.

Some Docs:
https://www.electronicproducts.com/...D_film_resistor_has_S_level_failure_rate.aspx
https://www.mouser.com/pdfdocs/ResistorTechnicalGuide-2.PDF
https://epsnews.com/2013/06/23/vishay-resistors-deliver-r-level-failure-rate/
 
Last edited:
Back
Top